What is this

This is a tool to decrypt Synology Cloud Sync encrypted files. This repository is at a very early POC stage.

Why it is here

I have a DS218+ and Microsoft is my new boss. This project is a playground of .Net.

How to use it

A console application is released to prove it works.

1. Download the executable release. It is a single window x86 executable, without the prerequisite of .Net installation.
2. Place the key.zip in the same directory as SimpleCLI-x86.exe
3. Drag the encrypted files and drop them on SimpleCLI-x86.exe
4. SimpleCLI-x86.exe will create a directory output in the same directory as itself and write the decrypted files into it.
5. Known limitation: this application is a POC, the unit test coverage is literally zero. But it should be safe to use. The file is hashed to compare with the md5 stored in the meta.

Special Thanks

This project is a remake of marnix/synology-decrypt. Many thanks to marnix ] who is the guy who did the reverse engineering.

Planned development

• Implement file hash
• Apply stream to read and process file data
• Implement a ringbuffer to copy between streams
• Apply async for io, the decrypting speed can reach 400MB/s, I have no idea if this async optimization is necessary.
• Implement Azure source connector
• Implement S3 source connector
• Implement WPF UX
• Apply Reactive